Device for in situ clearing of occlusions in tubing

ABSTRACT

An occlusion clearing device and system for removing material from an artificial tube in situ includes a clearing stem having aspiration and irrigation conduits, where the irrigation conduit is disposed interior to, and terminates within the aspiration conduit. Material enters the clearing stem through aspiration, and irrigation is provided within the aspiration conduit to assist in aspiration through the clearing stem. A handset includes aspiration and irrigation tubing connecting to sources therefor, and further includes valves to control the flow through the tubing and conduits. These valves may be operated simultaneously with an actuator located on the handset, which may be done with one hand. A coupler at the operative end allows the clearing stem to gain access to the artificial tube for clearing while maintaining a closed system with a ventilator. Reciprocating motion may be generated and provided to the clearing stem to aid in occlusion removal.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of U.S. ProvisionalApplication Ser. No. 62/243,458, filed on Oct. 19, 2015, the contents ofwhich are incorporated herein by reference in their entirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

This invention was made with government support under HD074310 awardedby the National Institutes of Health, and 0810029 and 0923861 awarded bythe National Science Foundation. The government has certain rights inthe invention.

FIELD OF THE INVENTION

The present invention pertains generally to the field of medicaldevices, and more specifically to a system for in-situ clearing ofocclusive material such as secretions in endotracheal tubes and othertubes in the body where secretions or other materials accumulate andnegatively impact tube patency.

BACKGROUND

The following is a description of the background of endotracheal tubes(ETTs). It should be understood that the device and method of thepresent invention is not limited to the clearing of ETTs but isapplicable to a range of artificial tubes such as indwelling catheters,pigtail catheters, abscess drains, and chest tubes and that ETTs arebeing discussed simply by way of example. It should also be understoodthat the device and method of the present invention is not limited tosecretions but is applicable to a range of accumulating and/or occludingmaterials such as blood, clots, and ingrown tissues/membranes.

Automated mechanical ventilation is often required for patients underanesthesia and for longer-term breathing assistance in compromisedpatients. Endotracheal tubes are placed in the upper respiratory tractof patients to provide direct airway access when connected to amechanical ventilator. Annually, 50 million ETTs are sold globally.Patients intubated with ETTs are unable to effectively clear lungsecretions, and therefore secretions can accumulate and partiallyocclude the inside of the ETT. This leads to increased airway resistanceand a potentially negative impact on patient health if not remedied.Without proper air humidification, the secretions also potentiallybecome dried, thick, and difficult to remove.

The most routine method to maintain ETT patency is periodic aspirationwith a suction catheter. The suction catheter is designed to bemomentarily inserted down the ETT manually while attached to a negativepressure source. There are two general types of suction catheters: openand closed. An open suction catheter requires the patient to bedisconnected from the ventilator for the suctioning procedure. A closedsuction catheter is enclosed in a protective sleeve and remains attachedto the ventilator circuit the entire time. Suctioning can occur withouthaving to shut off the ventilator or disconnect the patient, becausethere is a diaphragm that maintains an air-tight seal around thesuctioning catheter. Whether open or closed, the general suctionprocedure remains the same. With one hand stabilizing the proximal endof the ETT, the suction catheter is fed into the ETT with the oppositehand until the end is reached, being careful to not over-insert thecatheter beyond the tip of the ETT. While retracting the suctioncatheter, a valve is pressed enabling the negative pressure source toapply a vacuum to the inner lumen of the suction catheter to aspirateout secretions accumulated on the inner wall of the ETT. It is generallydesired for the entire suction procedure to be performed in 10-15seconds, or 5 seconds in children to minimize the impact of thesuctioning procedure on lung mechanics and respiration. Generally, apatient will require suctioning every 4-6 hours, but the process may beperformed with greater regularity if necessary. The procedure isrecommended on an as needed basis, not a regular interval, due to thedetrimental effect on the patient.

Attempts to clear the ETT using standard techniques are oftenineffective, time consuming, expensive, and an agonizing experience forthe patients, families, and health care providers. Standard methods canalso dislodge bacteria containing particles into the lungs. VentilatorAcquired Pneumonia (VAP) is a major source of infection in hospitals,and is often due to the direct path to the lungs for bacteria from ETTintubation. Standard suctioning has an effect on lung mechanics,including decreased tidal volume and lung compliance. Clinical sideeffects include hypoxia (low oxygen in blood), bradycardia (low heartrate), or atelectasis (collapse of part of the lung). In general, thelong term effects of acute changes in lung mechanics or cumulativeexposures to short term clinical side effects of suctioning on long termrespiratory health is not known. Still, minimizing the potentialnegative impacts of the suctioning process on the lungs is desirable.

Negative effects can be minimized with use of smaller diameter suctioncatheters, which allow improved airflow during the insertion of thecatheter and when actively suctioning. Guidelines suggest choosing asuction catheter whose outer diameter is less than half the innerdiameter of the ETT. However, with narrow ETTs (such as neo-natal orpediatric patients) this is difficult to achieve without severelylimiting secretion aspiration effectiveness using standard methods. Suchsmall diameter suction catheters may easily clog, depending on theconsistency of the secretions. In addition to airflow considerations,larger suction catheters may be difficult to insert if the catheterdiameter to ETT inner diameter ratio is larger than 0.7.

While the practice is now largely discouraged, occasionally physiologicsaline may be first instilled at the inlet to the ETT in an attempt tohydrate and thin the secretions to encourage its removal during thesubsequent suctioning procedure. Additional goals of saline instillationmay include lubricating and easing the insertion of the catheter itself,and/or elicitation of a cough from the patient to aid secretion removal.The current methods of instilling saline into ETTs are not precise andthere is risk of excess fluid entering the lungs and possibly causingdispersion of adherent contaminating material. Reports further suggestsaline instillation may cause greater blood oxygen desaturation thansuctioning without saline. Despite lack of evidence supporting salineinstillation and its potential risks, some clinicians continue thepractice.

When suctioning is unable to restore patency quickly, the only recourseis to replace the ETT, further raising the risk of VAP while alsodepriving the patient of oxygen until the patient is re-intubated andreconnected to the ventilator. In addition, the re-intubation processitself can agitate the patient's airway and lead to inflammation and/orinjury.

There remains a need to safely and quickly clear ETTs, while reducingthe negative impact the suction procedure has on the lung mechanics ofan already compromised patient.

SUMMARY OF THE INVENTION

The present invention is directed to an occlusion clearing device andsystem that may be used to clear secretions from ETTs and other tubes inthe body more quickly, thoroughly, and with less impact on the patient'slungs or other organs than any current method. The device may operatewithin a closed system, meaning that the connection to and function ofthe ventilator is not interrupted when secretion clearing is conducted.Gentle oscillation motion may be applied to assist in the clearing ofthe secretions or other material.

The occlusion clearing device includes a clearing stem having anaspiration conduit and an irrigation conduit within the aspirationconduit. This dual lumen stem allows distal delivery of low volume,continuous irrigation balanced with aspiration, allowing secretions tobe broken up and aspirated. Notably, the irrigation conduit terminatesinside the aspiration conduit, and si spaced a distance from theterminal end of the aspiration conduit, such that substantially all ofthe irrigation fluid provided to the operative end of the clearing stemremains within the clearing stem and is aspirated back up the clearingstem through the aspiration conduit. Therefore, contact of fluid ordebris with the endotracheal tube is avoided. A coupler may be used toconnect the endotracheal tube to the device, so that the operativedistal end of the clearing stem can be moved into the tube for clearingocclusive material. This coupler may also include a port for theventilator to attach, so that ventilation can continue throughout theprocess of occlusion clearing. The device also includes a handset havingaspiration and irrigation tubing that connects to respective sources,and valves for each to control the aspiration and irrigation flow,respectively.

These valves may be activated simultaneously with an actuator, which mayalso be locked in position to keep the aspiration and irrigation on oroff. Reciprocating motion, such as vibration, although not necessary,may also aid the break-up and aspiration of thicker secretions, alloweasier insertion (less hang up in tube), and to prevent secretions fromgetting stuck in the aspiration conduit. Implementing the motion appliedto the clearing stem, along with the irrigation and aspiration, whilemaintaining the closed system, may require the use of customconnections.

The occlusion clearing device, together with its particular features andadvantages, will become more apparent from the following detaileddescription and with reference to the appended drawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one embodiment of the occlusive clearingdevice.

FIG. 2 is a partial cutaway of the distal end of the clearing stem,positioned in an artificial tube having occlusive material being removedthrough the clearing stem.

FIG. 3A is a perspective view of one embodiment of the distal end of theclearing stem.

FIG. 3B is a cross-section of the distal end of the clearing stem ofFIG. 3A.

FIG. 4A is a perspective view of another embodiment of the distal end ofthe clearing stem.

FIG. 4B is a cross-section of the distal end of the clearing stem ofFIG. 4A.

FIG. 5A is a partial cross-section of a coupler connected to anendotracheal tube, in which the operative distal end of the occlusionclearing device is positioned within the coupler.

FIG. 5B is a partial cross-section of a coupler connected to anendotracheal tube, in which the operative distal end of the occlusionclearing device is inserted into the tube through the coupler.

FIG. 6 is a perspective view of one embodiment of the handset at theproximal end of the clearing stem.

FIG. 7A is a perspective view of another embodiment of the handset.

FIG. 7B is a perspective view of a third embodiment of the handset.

FIG. 7C is a perspective view of a fourth embodiment of the handset.

FIG. 7D and FIG. 7E are perspective views of a fifth embodiment of thehandset.

FIG. 8 is a partial cutaway of one embodiment of the handset showing theinterior components of the handset.

FIG. 9 is a cross-sectional view of one embodiment of the tubingjunction in the handset.

FIG. 10A is a schematic elevation view of one embodiment of theaspiration valve in the default position (closed).

FIG. 10B is a schematic elevation view of the aspiration valve of FIG.10A in the open position.

FIG. 11 is a partial cutaway of another embodiment of the handsetincluding a motor. Like reference numerals refer to like partsthroughout the several views of the drawings.

DETAILED DESCRIPTION

It is hereby noted that the term “in situ” is defined as performing anact on an element while the element is being utilized for its commonlyknown function. For example, performing the act of clearing fluids ormaterial from an ETT in situ refers to the fluids or material in an ETTwhile the tube is dwelling within the trachea or respiratory system of aliving being, human or other.

As shown in the accompanying drawings, the present invention is directedto an occlusion clearing device which employs several features that,individually and together, enhance aspiration effectiveness whileoccupying less cross-sectional area compared to existing devices on themarket. The need to occupy less cross-sectional area, while remainingsimilarly or more effective than existing devices is important, butparticularly so in small diameter tubes, such as neonatal ETTs withouter diameters less than or equal to 4 mm, for reason mentioned above.

The features of the present invention are aimed primarily at maintainingand improving flow of occlusive material (e.g. secretions, mucus, blood)within the aspiration lumen, which is highly prone to blockage due tothe small cross-sectional area. An irrigation lumen is disposed withinand runs parallel to the aspiration lumen, and terminates within theaspiration lumen before the clearing stem ends. The irrigation fluid(e.g. saline) sent to the distal end stays entirely within the clearingstem and does not exit into the tube to be cleared. Thus, the irrigationfluid helps lubricate the occlusive material once it is in theaspiration lumen and reduce viscosity of the material, which keeps theocclusive material from clogging the aspiration lumen during removal. Inaddition, the occlusion clearing device includes a coupler that permitsaccess of the clearing stem to the tube having the occlusion to becleared while still maintaining a closed system, such that the subjectcan remain on ventilation while the tube is being cleared.

In some embodiments, vibration may be delivered to the clearing stem ofthe device to assist in breaking up the occlusive material in the tubebeing cleared at the distal end, and also providing gentle agitationwith irrigation fluid to keep the occlusive material moving duringaspiration. The vibration may also reduce interfacial friction betweenthe clearing stem and the inner side of the tube being cleared, makingthe clearing stem easier to insert, which may be performed with just asingle hand.

As used herein, the terms “occlusion,” “secretion,” and “clog” may beused interchangeably, and refer to occlusive material in a tube disposedwithin a living subject, such as a patient. The subject may be a humanor any other animal. The tube may be any artificial or natural tubedisposed within a subject, and may be resident within the subject for aperiod of time. For instance, such tubes may include, but are notlimited to endotracheal and tracheostomy tubes. Such tube is to becleared when it has acquired material which is desired to be removed,such as foreign material or an amount of material (foreign or natural,such as secretions, mucus, and build-up of medication) that impairs thefunction of the tube, creates an unhygienic or uncomfortable situationfor the subject, or may otherwise be medically necessary or preferableto remove. Such material is referred to herein as “occlusive material.”Accordingly, occlusive material need not fully block or close off thetube to be cleared, but may refer to any material within the tube thatis desired to be removed.

With reference now to the Figures, FIG. 1 shows one embodiment of theocclusion clearing device 100 of the present invention. The device 100includes a clearing stem 120 having an operative distal end 130 on oneend, and a proximal end 135 on the opposite end. The distal end 130 ofthe clearing stem 120 may be fed into the tube to be cleared (notshown), such as through a coupler 190, in order to reach the occlusionfor removal. The clearing stem 120 may include depth markings 137 thataid the user during insertion into the tube to be cleared, to ensure theclearing stem 120 is not inserted beyond the end of the tube.

The clearing stem 120 is made up of an aspiration conduit 121 having anaspiration lumen 122 defined there through, and an irrigation conduit125 disposed within the aspiration conduit 121. During use, occlusivematerial is pulled into the aspiration conduit 121 of the clearing stem120 at the distal end 130, and irrigant from the irrigation conduit 125keeps the occlusive material sufficiently softened that it continues tomove proximally through the clearing stem 120 for removal and does notclog the clearing stem 120. At the proximal end 135, the device 100includes a handset 150 housing aspiration tubing 121 a and irrigationtubing 125 a. The aspiration tubing 121 a carries the aspiration out ofthe device through an aspiration port 154. The irrigation tubing 125 acarries irrigation into the device from an irrigation port 157. Thehandset 150 also includes valves controlling the flow of aspiration andirrigation through the respective tubing 121 a, 125 a, and consequentlyalso controls the flow rate in the clearing stem 120. Accordingly, thehandset 150 is intended to be gripped by a clinician or other user formaneuvering and actuation of the device 100 for aspiration of occlusivematerial from the tube to be cleared.

In at least one embodiment, a protective sleeve 138 may cover theclearing stem 120 and prevent it from being contaminated by theenvironment. For example, the protective sleeve 138 may maintain asterile environment for the clearing stem 120 once the device 100 issterilized. At a minimum, the protective sleeve 138 prevents a user fromdirectly touching the clearing stem 120, and protects it from dirt anddebris that may be in the air. The protective sleeve 138 may connect atone end to the coupler 190 and at the other end to the handset 150, suchas at an adapter 153, so that the protective sleeve 138 spans the entirelength of the clearing stem 120 between each of these components.

As shown in FIG. 2, the distal end of the clearing stem 120 is operativeto withdraw occlusive material 5 from a tube 7. The occlusive material 5may include but is not limited to secretions, mucus, phlegm, blood, etc.In use, the distal end 130, and specifically the distal tip 131, of theaspiration conduit 121 is positioned in close proximity to the occlusivematerial 5 that is to be removed from the tube 7. Aspiration is appliedto draw the occlusive material 5 into the aspiration lumen 122, and isremoved from the tube 7 by being pulled in an aspirational flowdirection 128 away from the distal end 130 of the device 100.

As is depicted throughout FIGS. 2-4B, the aspiration conduit 121includes at least one opening 132 in the distal tip 131. In at least oneembodiment, the distal tip 131 includes an opening at the terminal endof the aspiration conduit 121. In some embodiments, as shown in FIGS. 3Aand 4A, the distal tip 131 includes a plurality of openings 132 in theaspiration conduit 121. Any number and placement of openings 132 iscontemplated herein. For instance, one of these openings 132 may belocated at the terminal end of the aspiration conduit 121, and at leastone additional opening 132 may be formed in the wall of the aspirationconduit 121 at the distal tip 131 spaced away from the terminal end ofthe distal tip 131. FIG. 3A shows two openings 132 directly oppositeeach other across the diameter of the aspiration conduit 121. The numberand placement of these openings may vary in order to optimize theremoval of occlusive material. For instance, two openings 132 may bepresent and may be set back or proximal from the terminal end of thedistal tip 135 by the same distance or different distances, such thatthe opening on one side is closer to the distal tip of the aspirationconduit 121 than the other opening. Typically the most distal edge ofthe most distal openings 132 will be a preselected distance from theterminal end, such as at least approximately one-half diameter (oneradius) back from the terminal end of the distal tip 135 of theaspiration conduit 121 or farther. For instance, the openings 132 shownin FIG. 3A for an aspiration conduit 121 having an internal diameter0.036 inches may be spaced back from the terminal end by a distance inthe range of 0.009 to 0.100 inches, and may be in the range of 0.012 to0.050 inches, and may preferably be 0.015 inches. The openings 132 shownin FIG. 3A for an aspiration conduit 121 having and internal diameter0.057 inches may be spaced back from the terminal end by a distance inthe range of 0.012 to 0.125 inches, and may be in the range of 0.018 to0.060 inches, and may preferably be 0.025 inches.

The opening(s) 132 are dimensioned to permit occlusive material 5 topass there through, and may be any size and shape as permits passage ofocclusive material 5. For instance, in at least one embodiment as shownin FIGS. 2-4B, the opening(s) 132 are circular. Typical diameters forcircular openings 132, such as shown in FIG. 3A, for an aspirationconduit 121 having an internal diameter 0.036 inches (such as used toclear a 2.5 mm tube) may be in the range of 0.018 to 0.045 inches, ormore preferably 0.025 to 0.036 inches, and may be 0.030 inches. Typicaldiameters for circular openings 132 such as shown in FIG. 3A for anaspiration conduit 121 having an internal diameter of 0.057 inches (suchas used to clear a 3.5 mm tube) may be in the range of 0.025 to 0.067inches, or more preferably 0.030 to 0.060 inches, and may be 0.050inches. In at least one other embodiment, the terminal opening 132 maybe circular and additional openings 132 at the distal tip 131 may beoval or oblong in shape, and may have a longer dimension either parallelto the length of the aspiration conduit 121 or in the direction of thecircumference of the aspiration conduit 121. For instance, openings 132in the aspiration conduit 121 may be oval in shape and have a longerdimension perpendicular to the length of the aspiration conduit 121, inthe direction of the circumference of the aspiration conduit 121, so asto increase the area for receiving the occlusive material 5 into theaspiration lumen 122. Regarding size, the opening(s) 132 are generallyapproximately the same diameter or smaller than the diameter of theaspiration lumen 122. These are only examples provided for illustrativepurposes, and should not be considered limiting.

The occlusive material 5 is sucked into the clearing stem 120,specifically the aspiration lumen 122, and aspirated back towards theproximal end of the device as shown by the aspirational flow arrows 123.Suction pressure is applied at the proximal end of the device 100 toestablish aspirational flow 123, and may be between 50 and 200 mm Hg. Inat least one embodiment, the aspiration pressure that drives aspirationflow 123 is preferably between 60 and 150 mm Hg. In still furtherembodiments, the aspirational pressure is between 80-130 mm Hg, and maypreferably be 120 mm Hg. Greater and lower aspirational pressures andresulting flow rates are also possible and contemplated herein.

The size or diameter of the clearing stem 120, and specifically theaspiration conduit 121, will vary, but is small enough to be insertedinto a tube 7 to be cleared, such as an endotracheal tube (ETT) ortracheostomy tube, although any tube 7 having occlusive material 5 inneed of removal is contemplated. Therefore, the aspiration conduit 121is also large enough to accommodate occlusive material 5 therein as itis aspirated away. The wall of the aspiration conduit 121 issufficiently thick to provide structure for the clearing stem 120 andwill not collapse under the aspirational pressure when applied, and yetis thin enough to be navigated through the tube 7 to reach the occlusivematerial 5 for clearing. For example, for a 2.5 mm ETT, one embodimentof the aspiration conduit 121 has an internal diameter of 0.030 to 0.057inches. This internal diameter corresponds to the diameter of theaspiration lumen 122. In other embodiments, the internal diameter is inthe range of 0.035 to 0.045 inches, and may preferably be 0.036 inchesin some embodiments. The wall thickness of the aspiration conduit 121may be altered to affect the stiffness, ability to withstand highersuction pressures, or to adjust the outside diameter of the aspirationconduit. For example, typically wall thicknesses for the aspirationconduit 121 may be in the range of 0.002 to 0.012 inches in someembodiments. In certain embodiments, the wall thickness of theaspiration conduit 121 may be in the range of 0.004 to 0.010, morepreferably may be 0.006 inches in certain embodiments.

In examples where a 3.5 mm ETT is to be cleared, the aspiration conduit121 may have an internal diameter of 0.045 to 0.080 inches. In someembodiments, the internal diameter is the range of 0.055 to 0.070inches, and may preferably be 0.057 inches. The wall thickness of theaspiration conduit 121 may be in the range of 0.002 to 0.012 inches. Insome embodiments, the wall thickness may be in the range of 0.004 to0.010 inches, and may more preferably be 0.006 inches in someembodiments. Of course, smaller and larger wall thicknesses and lumendiameters are also contemplated herein, depending on the size of thetube 7 to be cleared and the type, character and amount of occlusivematerial 5 to be removed.

As depicted in FIGS. 2-4B, the clearing stem 120 also includes anirrigation conduit 125 having an irrigation lumen 126 therein. Theirrigation conduit 125 is at least partially disposed within theaspiration lumen 122 of the clearing stem 120, and provides irrigant 127to the distal end of the clearing stem 120. The irrigation conduit 125ends within the aspiration lumen 122, such that the irrigation conduit125 is entirely within the aspiration lumen 122 at the distal end 130 ofthe clearing stem 120. As occlusive material 5 is drawn into theclearing stem 120 through the opening(s) 132, it mixes with irrigant 127being gently expelled from the irrigation lumen 126 into the aspirationlumen 122, as best shown in FIGS. 2 and 4B. This mixing of irrigant 127and the occlusive material 5 helps to lubricate the occlusive material 5within the device 100 and prevent it from clogging the aspiration lumen122, and therefore maintain the patency of the clearing stem 120. Asmost clearly shown in FIGS. 3B and 4B, the irrigation conduit 125terminates within the aspiration lumen 122 before, or proximal to, theopening(s) 132 at the distal tip 131. This retracted position allows theirrigant 127 to exit the irrigation lumen 126 and mix with occlusivematerial 5 while remaining entirely within the clearing stem 120. Inother words, the positioning of the irrigation conduit 125 within theaspiration lumen 122 prevents irrigant 127 from leaking out of orexiting the clearing stem 120 through the opening(s) 132. This isparticularly important in cases where the tube 7 being cleared is an ETTor tracheostomy tube residing in the subject patient's respiratorytract, where further fluid added to the tube, and potentially thepatient's lungs or airway, should be avoided.

Both the internal diameter of the irrigation conduit 125 (the diameterof the irrigation lumen 126) and the delivery pressure of irrigant 127provided at the proximal end of the device 100 affect irrigant flow rateto the distal end of irrigation conduit 125. The irrigant flow ratethrough the irrigation lumen 126 is coordinated with aspiration flowthough the aspiration lumen 122 to ensure that no irrigant 127 exits theopenings 132 in the distal end 130 of the clearing stem 120. Theirrigation lumen 126 may have a diameter in the range of 0.005 to 0.015in some embodiments. In other embodiments, it may be in the range of0.008 to 0.013 inches, and may preferably be about 0.010 inches. Theseare but a few preferred diameters, and other diameters larger andsmaller are also contemplated. The irrigation lumen 126 diameter maydepend on the size of the aspiration lumen 122 into which the irrigationconduit 125 is placed.

The irrigation conduit 125 may have different wall thicknesses dependingon the desired stiffness, ability to withstand higher irrigantpressures, or based on the diameter of the aspiration conduit 121, whichmay alter the size of the aspiration lumen 122 and aspirant flow rate.For instance, in some embodiments, the irrigation conduit 125 may have awall thickness in the range of 0.0005 to 0.0030 inches. In someembodiments, the wall thickness is in the range of 0.0008 to 0.0015inches, and may preferably be 0.0010 inches.

The delivery pressure of irrigant 127 may vary, such as from 1 psi to 20psi. In some embodiments, the irrigation pressure may be from 2 psi to15 psi. In still other embodiments, the irrigation pressure may be from6 psi to 10 psi, and may preferably be 7 psi. Irrigant flow rates mayvary, such as from 0.003 g/sec to 0.100 g/sec in some embodiments. Incertain embodiments, the irrigant flow rate may be from 0.010 g/sec to0.050 g/sec. In still other embodiments, it may be from 0.015 g/sec to0.035 g/sec, and may preferably be 0.025 g/sec.

The physical dimensions of the aspiration conduit 121 and irrigationconduit 125 can be altered to affect the aspiration flow 123 andirrigant flow 128, respectively. If the delivery pressure of irrigant127 and the aspiration pressure are fixed and unchanging, increasing thediameter of the irrigation lumen 126 will increases the irrigant flow128 relative to the aspiration flow 123. Likewise, decreasing thediameter of the irrigation lumen 126 will decrease the irrigant flow 128relative to the aspiration flow 123. The wall thicknesses of theirrigation conduit 125 and aspiration conduit 121 can also affect therelative flows. As an example, if the aspiration conduit 121 innerdiameter and irrigant conduit 125 outer diameter remain fixed,increasing the irrigant conduit 125 wall thickness will necessarilyreduce the available area in the irrigant lumen 126, thereby reducingthe irrigant flow 128.

Both the irrigation conduit 125 and the aspiration conduit 121 may bemade of polymeric materials typically used for medical catheterapplications including, but not limited to, polyurethane,polyvinylchoride, polyimide, and polyamide including copolymers andblends that can be utilized to adjust the physical properties to balancestrength, stiffness, hardness, etc. Additionally, the materials,dimensions or both maybe altered along the length of the clearing stem120 from the distal end 130 to proximal end 135 to provide a balance ofstrength, stiffness, hardness, and other factors as may be beneficial atdifferent portions of the clearing stem 120. Reinforcements may beutilized to alter these properties. Such reinforcements may includeadditives to the polymeric material, such as glass fiber or spiral andbraided wire reinforcement.

In some embodiments, the clearing stem 120 may have variable stiffnessalong its length. For instance, a stiffer material may be used at theproximal end 135 for maximum aspiration lumen 122 diameter whilemaintaining or improving pushability. The distal end 130, however, maybe flexible to prevent tissue damage if contact with biological surfacesoccurs. In some embodiments as in FIGS. 4A and 4B, the distal tip 131may be made of a different material than the rest of the clearing stem120. For instance, the distal tip 131 may be made of a softer or moreflexible material than the rest of the clearing stem 120. This allowsfor a more rigid material to be used throughout most of the length ofthe clearing stem 120 to maximize the pushability of the clearing stem120 as it is being inserted into the tube 7 and a more flexible materialto be used at the distal tip 131 to ensure tissue damage is minimized inthe event that the clearing stem 120 is inadvertently over inserted.Examples of a softer material for use in the distal tip 131 may includematerials having a Shore hardness or durometer in the range of 30 A to100 A (60 D), where “A” refers to the Shore A scale and “D” refers tothe Shore D scale, which partially overlap. In some embodiments, thesofter distal tip 131 material may be in the range of 70 A (12 D) to 90A (45 D). In certain embodiments, it may be about 82 A (35 D). Incontrast, the more rigid material used for the proximal end 135 of theclearing stem 120 may be in the range of 80 A (32 D) to 90 D. In someembodiments, the more rigid material may be in the range of 95 A (50 D)to 80 D, and may preferably be 72 D. The particular materials used foreither the softer or more rigid sections of the clearing stem 120 may bepolymeric materials and blends as are commonly used in medical gradecatheters, although any material suitable for medical use may be used.These are illustrative examples, and are not intended to be limiting.

The irrigation conduit 125 and aspiration conduit 121 may be separatecomponents, as shown in FIG. 3B. In other embodiments, as in FIG. 4B,the irrigation conduit 125 and aspiration conduit 121 may be integrallyformed, such as made from a single multi-lumen extrusion. In still otherembodiments, the irrigation conduit 125 and aspiration conduit 121 maybe formed separately, but may be secured to one another in the device100. The multi-lumen extrusion can be a more rigid material, aspreviously discussed, and the distal tip 131 can be a more compliantmaterial bonded to the end of the extrusion. This configuration allowsthe irrigation lumen 126 to be set back from the terminal end of theclearing stem 120 so that substantially all of the irrigant 127 thatexits the irrigation lumen 126 is aspirated back in the aspiration flow123 direction to the proximal end of the occlusion clearing device 100before it can exit the openings 132.

As shown in FIGS. 5A and 5B, the occlusion clearing device 100 furtherincludes a coupler 190 at the distal end 130 of the clearing stem 120that provides a connection point for access to the tube 7 havingocclusive material to be cleared, such as an ETT. The coupler 190includes a clearing stem connector 191 having a chamber 194 therein intowhich the distal end 130 of the clearing stem is passed. The protectivesleeve 138 may attach to the clearing stem connector 191 to protect theclearing stem 120 outside of the coupler 190. The coupler 190 alsoincludes a tube connector 195 that attaches to the tube 7. Theconnection between the tube 7 and tube connector 195 is selectivelyreversible, such that the device 100 can be attached for use and thenremoved when clearing is complete. Attachment of the tube 7 and tubeconnector 195 can be by any suitable means that provides a fluidicallytight seal that is selectively reversible. For example, the tubeconnector 195 may snap on to the tube 7, or may have threading to attachto the tube 7 in a screw-type fashion. The tube connector 195 is influid communication with the chamber 194 within the clearing stemconnector 191, such that the clearing stem 120 can be moved between theclearing stem connector 191 and the tube connector 195 for accessing thetube 7 for clearing.

In at least one preferred embodiment, the coupler 190 further includes adiaphragm 192 that creates a fluidic seal around the clearing stem 120when it is positioned inside the coupler 190. For instance, thediaphragm 192 may be located in the clearing stem connector 191, suchthat the clearing stem 120 must pass through the diaphragm 192 in orderto enter the coupler 190, and specifically the chamber 194. Thediaphragm 192 seals off the coupler 190, forming a closed system betweenthe tube 7 and the clearing stem 120 during use. Also, in someembodiments, the coupler 190 may also include additional port(s), suchas a ventilator port 196 that attaches to the ventilator system on whicha patient may be established. Accordingly, when the ventilator system isconnected to the ventilator port 196 and the tube 7 is connected to thetube connector 195, the diaphragm 192 creates a seal around the clearingstem 120, forming a closed system such that the patient can continue tobe mechanically ventilated through the ventilator port 196 without anyair leaks during the occlusion removal process. In other embodiments,however, the occlusion clearing device 100 may be used in an open systemin which the patient is not on a ventilator system, or the ventilatorsystem is temporarily suspended for occlusion clearing.

In use, the clearing stem 120 is positioned into the chamber 194 of theclearing stem connector 191, and the tube 7 is connected to the tubeconnector 195, as depicted in FIG. 5A. The clinician or user then movesthe clearing stem 120 through the coupler 190 and into the tube 7, asshown in FIG. 5B, until the distal end of the clearing stem 120 is inproximity to the occlusive material to be cleared (as in FIG. 2). Theocclusive material is removed from the tube 7, as shown in FIG. 2, andthe clearing stem 120 is withdrawn from the tube 7, returning again tothe coupler 190 as seen in FIG. 5A. Aspiration and irrigation may occurat any time during this process, including when the clearing stem 120 isbeing advanced into the tube 7 and as it is withdrawn from the tube 7.The clearing stem 120 may be moved in and out of the tube 7 by graspingthe clearing stem 120 through the protective sleeve 138 and inching itforward or back, or it may be moved by pushing on the handset 150 at theproximal end 135 of the clearing stem 120. The coupler 190 may also beheld steady with one hand if desired.

In some embodiments, the coupler 190 may also include a lavage port 193on the clearing stem connector 191, as shown in FIGS. 5A and 5B. Thelavage port 193 allows the user to clean or flush the distal end of theclearing stem 120 after use or between insertions. Accordingly, thelavage port 193 is in fluid communication with the chamber 194 therein.Lavage fluid, such as saline or other biologically suitable wash fluid,may be introduced into the lavage port 193 to remove occlusive materialor other matter the clearing stem 120 may have picked up from the tube7. This lavage fluid may then be aspirated through the aspiration lumen122 of the clearing stem to remove it from the coupler 190.

As shown throughout FIGS. 1 and 6-8, the occlusion clearing device 100also includes a handset 150 at the proximal end 135 of the clearing stem120. The handset 150 is designed to be held in a single hand of the userfor positioning and use of the occlusion clearing device 100.Accordingly, the handset 150 includes a body 151 that is gripped by theuser, and houses various other components for actuating the device 100.For instance, the handset 150 provides the user the ability to controlthe aspiration flow 123 and the irrigation flow 128 with one hand,explained in detail below.

As illustrated in FIG. 6, the handset 150 is located at the proximal endof the clearing stem 120. The clearing stem 120 connects to the handset150 through an adaptor 153. The adaptor 153 may connect directly orindirectly to the body 151 of the handset 150. The adaptor 153 alsoprovides a connection point for the protective sleeve 138 (not shown) atthe proximal end of the device 100, thus protecting the proximal end ofthe clearing stem 120.

As depicted in FIG. 8, the handset 150 includes an aspiration port 154that connects to an aspiration source (not shown) such as a vacuum pumpor other suitable source of suction. The handset 150 further includesaspiration tubing 121 a disposed through at least a portion of the body151 of the handset 150 and connecting the aspiration port 154 to theaspiration lumen 122 of the clearing stem 120 as it joins to the handset150 through the adaptor, as shown in FIG. 6. The aspiration tubing 121 ais in fluid communication with both the aspiration lumen 122 of theclearing stem 120 and the aspiration port 154 such that suction drawn atthe source is communicated through the aspiration port 154, through thetubing 121 a, and through the aspiration lumen 122 to the distal tip 131of the clearing stem 120 to draw occlusive material 5 into the clearingaspiration lumen 122 for removal.

Similarly, as seen in FIG. 8, the handset 150 also includes anirrigation port 157 that connects to a source of irrigant (not shown),such as saline or other inert fluid. The handset 150 further includesirrigation tubing 125 a disposed through at least a portion of the body151 of the handset 150 and connecting the irrigation port 157 to theirrigation lumen 126 of the clearing stem 120. The irrigation tubing 125a is in fluid communication with the irrigation port 157 and theirrigation lumen 126 so that irrigant provided from the source (notshown) to the irrigation port 157 is moved through the irrigation tubing125 a and through the irrigation lumen 126 to the distal end 130 of theclearing stem 120, where it exits into the aspiration lumen 122 andmixes with occlusive material 5 therein to lubricate it for removal.

In some embodiments, the aspiration port 154 and irrigation port 157connect directly to the body 151 of the handset. In other embodiments,as in FIG. 7D, the aspiration port 154 and irrigation port 157 may bespaced apart from the body 151 of the handset, and connect indirectlythrough aspiration tubing 121 a and irrigation tubing 125 a,respectively. Accordingly, at least a portion of aspiration tubing 121 aand irrigation tubing 125 a is positioned within the body 151 of thehandset 150 and connects the aspiration port 154 and irrigation port 157to the appropriate lumens 122, 126 of the clearing stem 120, and atleast a portion of the aspiration tubing 121 a and irrigation tubing 125a may be positioned or extend beyond the body 151 of the handset 150 forjoining to distanced aspiration port 154 and irrigation port 157. Eitheror both of the aspiration port 154 and irrigation port 157 may be spacedapart from the body 151 of the handset 150.

The handset 150 may also include a viewing window 156 which coincideswith a portion of the clearing stem 120 and/or aspiration tubing 121 aand permits a user to see and visually monitor the occlusive material 5as it is aspirated through the device 100. The viewing window 156 may belocated anywhere along the clearing stem 120 or aspiration tubing 121 a.For instance, in some embodiments, the viewing window 156 is located onthe distal side of the handset 150, as shown in FIG. 6. In otherembodiments, the viewing window 156 is located proximally of the handset150 along aspiration tubing 121 a, as shown in FIG. 7A. The viewingwindow 156 may be a portion of tubing, a window set into tubing, or maybe an entire segment of tubing. In a preferred embodiment, the viewingwindow 156 is transparent to allow visual perception of occlusivematerial 5 and irrigant 127 as it is aspirated through and out of thedevice 100. For instance, the amount, color and consistency of theocclusive material 5, and whether any blood is also present, may bevisually monitored using the viewing window 156.

The handset 150 also includes a tubing junction 180, as shown in FIGS. 8and 9. The tubing junction 180 provides a way of combining theirrigation tubing 125 a and aspiration tubing 121 a in order to get theirrigation conduit 125 inside the aspiration lumen 122 in the clearingstem 120. In other words, the tubing junction 180 joins the proximalportions of the irrigation conduit 125 and aspiration conduit 121 fromthe clearing stem 120 with their respective distal tubings 125 a and 121a in a way that enables separate irrigation and aspiration through asingle combined clearing stem 120.

With particular reference to FIG. 9, the tubing junction 180 includes afirst passage 181 that receives the aspiration tubing 121 a in thehandset 150. This first passage 181 is therefore in fluid communicationwith the aspiration tubing lumen 122 a such that aspirated materials canmove from the first passage 181 into the aspiration tubing 121 a in thedirection of aspiration flow 123. The tubing junction 180 also includesa second passage 182 that receives the irrigation tubing 125 a in thehandset 150. The second passage 182 is in fluid communication with theirrigation tubing lumen 126 a, and therefore also with irrigant movingin the direction of irrigation flow 128. The tubing junction 180 furtherincludes a third passage 184 that receives the aspiration conduit 121and irrigation conduit 125 of the clearing stem 120.

In the embodiment of FIG. 9, the aspiration conduit 121 begins in thethird passage 184 of the tubing junction 180, but the irrigation conduit125 extends into the second passage 182. Irrigant 127 from theirrigation tubing 125 a in the second passage 182 enters the irrigationconduit 125 in the second passage 182, and continues in the direction ofirrigation flow 128 on into the clearing stem. Since the aspirationconduit 121 of the clearing stem only begins in the third passage 184,the irrigation conduit 125 is able to enter the aspiration lumen 122 inthe third passage 184. In some embodiments, as in FIG. 9, the irrigationconduit 125 extends into the second passage 182, but is separate fromthe irrigation tubing 125 a that may also be located in the secondpassage 182. In other embodiments, the irrigation conduit 125 and tubing125 a may join together, such as in the second passage 182 of the tubingjunction 180. For instance, at least one of the irrigation tubing 125 aor conduit 125 may taper to a common diameter shared between them, sothat irrigant 127 pushed from the irrigation tubing 125 a into theconduit 125 is directed into the irrigation conduit 125. These are but afew examples. Other embodiments may contemplate other ways of directingthe irrigant 127 into the irrigation conduit 125 of the clearing stem120.

Additionally, a seal 183 is provided in the tubing junction 180, such asin the second passage 182, third passage 184, or the space there betweento create a fluid tight or hermetic barrier around the irrigationconduit 125 or tubing 125 a within the tubing junction 180. Forinstance, the seal 183 may be provided in the second passage 182 aroundthe irrigation conduit 125, as depicted in FIG. 9. The seal 183 createsa fluid communication between the aspiration lumen 122 from the clearingstem 120, the third passage 184 and first passage 181 of the tubingjunction 180, and the aspiration tubing lumen 122 a for aspiration. Theseal 183 functions to exclude the irrigant 127 from this aspirationfluid communication. The seal 183 may be any material suitable forcreating a fluid tight barrier, such as adhesive, gel, or other similarmaterial. Further, it should be appreciated that although the embodimentof FIG. 9 shows the aspiration conduit 121 and tubing 121 a as separate,in at least one other embodiment, the aspiration conduit 121 and tubing121 a may join or merge at some point in the tubing junction 180. Instill other embodiments, the aspiration conduit 121 and tubing 121 a maybe the same, and the irrigation conduit 125 may penetrate or passthrough the wall of the aspiration conduit 121, in which case the seal183 would be formed around the irrigation conduit 125 at this point.

As shown in FIGS. 8 and 10A-10B, the handset 150 also includes valvesthat control each of the aspiration 123 and irrigation 128 flow.Specifically, a first valve 170 is interposed in the aspiration tubing121 a that connects the aspiration port 154 to the aspiration conduit121 of the clearing stem 120. A second valve 172 is interposed in theirrigation tubing 125 a that connects the irrigation port 157 to theirrigation conduit 125 of the clearing stem 120. The valves 170, 172 maybe opened or closed to turn the aspiration 123 and irrigation 128 flowon or off, respectively. For instance, the valves 170, 172 may each havea valve top 174, a body 175, and at least one but preferably more thanone arm 176, as shown in FIGS. 10A and 10B. The valve top 174 may beraised or lowered to change the valve 170, 172 between open and closedpositions. Additionally, the valves 170, 172 may be any type of valvesuitable for opening and closing a fluid flow path, such as but notlimited to membrane valves and spring valves. As used herein, “fluid”may mean liquid, gas, combinations thereof, and may further includeparticulates dispersed therein, such as occlusive material 5.

For instance, in at least one embodiment, the valves 170, 172 aremembrane valves that are closed when the valve top 174 is in the raisedposition, as in FIG. 10A, and open when the valve top 174 is lowered ordepressed, as in FIG. 10B. Here, the first valve 170 is shown forillustrative purposes, but it should be understood that the second valve172 may work in a similar fashion. For instance, the aspiration tubing121 a connects to each arm 176 of the first valve 170 such that thefirst vale 170 is interposed in the fluid flow path of aspiration 123.When the first valve 170 is closed, as in FIG. 10A, the aspiration flow123 is halted at the body 175 of the first valve 170 and not permittedto pass. Aspiration is prevented from flowing through the handset 150.When the valve top 174 is lowered, as in FIG. 10B, the membrane valvethat is the first valve 170 opens, permitting aspiration flow 123through the valve body 175, into the opposing arm 176, and on into theaspiration tubing 121 a on the other side of the first valve 170.Accordingly, aspiration flow 123 is permitted through the handset 150.The example of membrane valves are illustrated here, but it should beappreciated that other types of valves, such as spring valves, mayoperate in the reverse manner (where the valve is open when the valvetop 174 is raised and closed when the valve top 174 is lowered). Varioustypes and operations of valve are contemplated here.

The handset 150 may further include an actuator 161 located on thehandset 150, such as on the body 151, that can be pressed, moved, orotherwise activated to engage and/or disengage the first and secondvalves 170, 172 to move them between operative and inoperativepositions. In at least one embodiment, the actuator 161 is a button thatis activated by rotation, as in FIG. 7A, or by pressing, as in FIGS. 7Band 7C. In other embodiments, the actuator 161 may be a portion of orthe entire top surface 152 of the handset 150, as in FIGS. 6 and 7D-7E.In such embodiments, the top surface 152 may be movably connected to thebody 151, such as by a hinge connection or other suitable mechanism.When the actuator 161 portion is pressed, the entire top surface 152 maypivot down, as indicated by the directional arrow in FIG. 6. When notengaged, the top surface 152 of the handset 150 may return to a raisedposition. These are just a few illustrative examples of the form andoperation of the actuator 161, and are not intended to be limiting. Forall of these examples, the actuator 161 may be activated or acted on bythe hand of the user holding the handset 150, such as by pressing withthe heel or edge of the hand or with a finger. Accordingly, the handset150 may be both held and operated single-handedly by a user.

When activated, the actuator 161 engages the first and second valves170, 172 within the handset 150 to open or close the valve. Forinstance, the actuator 161 pressing down on the valve tops 174 of thefirst and second valves 170, 172 will open or close the valves,depending on the type of valve it is. In at least one embodiment, thevalves 170, 172 can thus be opened or closed simultaneously; although inother embodiments it is contemplated they may be operated independentlyof one another. Moreover, in some embodiments it is contemplated thatpartial opening or closing of the valves 170, 172 may be possible byengaging the actuator 161 variably or by degrees.

The handset 150 may also include a lock 162 that retains the actuator161 in a particular position, and as a result also maintains the firstand second valves 170, 172 in a corresponding position. For example, thelock 162 may keep the actuator 161 in a depressed or rotated position,which in turn keeps the first and second valves 170, 172 in thecorresponding open or closed position (or partially opened or closedposition, depending on the embodiment). Accordingly, a user may selectthe desired position for the actuator 161 and then lock it in place,thereby keeping the aspiration and irrigation either one or off. Theuser therefore does not have to continually hold down the actuator 161,but may set it and then turn their attention to the distal end of thedevice 100 or the viewing window 156 to monitor the occlusion clearingprocess. The lock 162 is also selectively releasable to permit theactuator 161 to move to another position when desired.

Various types of locks 162 are contemplated. For instance, in at leastone embodiment as shown in FIGS. 6 and 7B, the lock 162 a may be a slidelock that moves along a track between positions. In one position, thelock 162 a may engage the actuator 161 and keep it in restrictedengagement in a particular setting, such as up or down. In anotherposition along the slide track, the lock 162 a disengages from theactuator 161, which is then free to move to a different position. Thelock and unlock positions of the lock 162 a may be anywhere along thetrack as permits engagement and disengagement of the actuator 161. In atleast one other embodiment, as depicted in FIG. 7A, the actuator 161 mayitself be a lock 162 d, such that the actuator 161 may be pressed toactivate and rotated to lock in position, or may be rotated to bothactivate and lock at the same time. In other embodiments, as in FIG. 7C,the lock 162 b may be a plate or other substantially planar device thatmay slidingly engage at least part of the actuator 161 to retain it inposition. For instance, the lock 162 b may be inserted around or underat least a portion of the actuator 161 when it is raised, as indicatedby the directional arrow, so as to prevent it from being pressed down.In this case, the lock 162 b may prevent the actuator 161 from beingdepressed, keeping the valves 170, 172 either open or closed dependingon the corresponding position. In still other embodiments, as in FIG.7D, the lock 162 c may be a pin that is inserted into an aperture 165 inthe body 151 of the handset 150 to engage the actuator 161. The lock 162c may be selectively removed from the aperture 165 to release theactuator 161, as in FIG. 7E. Accordingly, the lock 162 c may be attachedto a mount 164 or other structure that movably connects the lock 162 cto the handset 150. As shown in FIG. 7E, the mount 164 may pivot orswing about a fixed point so as to move the lock 162 c into and out ofalignment with the aperture 165 for engaging or disengaging the actuator161, respectively.

It should also be evident that the various types of locks 162 a, 162 b,162 c may be configured to work with different types of actuators 161.For instance, a slide lock 162 a is illustrated for use with both ahinge type actuator (as in FIG. 6) and a button type actuator 161 (as inFIG. 7B).

The occlusion clearing device 100 may be used with only aspiration andirrigation. In some embodiments, however, reciprocating motion may alsobe applied to the clearing stem 120 to assist the distal tip 131 incontacting the occlusive material 5 in the tube 7 to be cleared, and inkeeping the occlusive material 5 moving through the aspiration lumen 122of the clearing stem 120 for removal and maintain patency of theclearing stem 120. Therefore, in some embodiments, as in FIG. 11, thehandset 150 may also include a motor 160 that generates reciprocating oroscillating motion. As used herein, “reciprocating” and “oscillating”may be used interchangeably to refer to motion that is back and forth inan axial direction. A shaft 167 connects to the motor 160 and transmitsthe reciprocating motion to the clearing stem 120, such that theclearing stem 120 is gently moved back and forth by the reciprocatingmotion 168. For instance, the shaft 167 may connect the motor 160 to thetubing junction 180, so as to provide the reciprocating motion 168 tothe tubing junction 180, which in turn conveys the motion 168 to theclearing stem 120 attached to and extending from the opposite side ofthe tubing junction 180. The shaft 167 is therefore made of a rigidmaterial, such as polymer or metal having a hardness sufficient tomaintain its structure and avoid bending upon the application ofreciprocating motion from the motor 166. The motor 166 may be driven byany suitable power source, such as DC power from a wall-driven powersupply connected by a power cord 169, or by battery, or both.

The motor 166 may be any suitable motor capable of generating gentlereciprocating motion, such as, but not limited to, voice coil motors(VCM); DC motors; piezoelectric transducers, including amplifiedpiezoelectric actuator (APA) motors such as those disclosed in U.S. Pat.No. 6,465,936 (Knowles, et al.), whose entire disclosure is incorporatedby reference herein; piezoelectric actuators; active polymer compoundactuators; solenoid motors; pneumatic motors; magnetorestrictivetransducers; and electrorestrictive transducers.

For instance, in some embodiments the motor 166 may be a voice coilmotor (VCM) as are commercially available. For instance, the VCM mayinclude a displaceable motor shaft with magnets mounted thereto and coilwindings wound around the VCM body. When activated, an electric currentis applied through the coil windings, creating a magnetic field insidethe coil windings. The non-uniform magnetic field at the ends exerts aforce on the magnets on the shaft. Alternating the current alternatesthe direction of the magnetic field gradients and results in areciprocating motion of the motor shaft with respect to the VCM body.The magnitude of the force is determined by the magnetic flux density,which is proportional to the number of turns per length of the coil,current magnitude, cross-sectional area of the coil, as well as thestrength of the permanent magnets. Springs in the VCM absorb the energyassociated with abrupt changes in the direction of the inertial force ofthe magnets and VCM body when actuated. By way of example only, thespring constant of the springs can range from 0.5-5 lb/in, and morepreferably 1.5-2.5 lb/in. The relative positions of the coil windingsand magnets can be reversed, such that the coil windings are wounddirectly around the motor shaft and the magnets are positioned aroundthe VCM body and thus do not interfere with the motor shaft'sreciprocation.

Alternatively, the VCM may be a dual coil motor or actuator. Instead ofusing magnets, two coil windings are used wherein one coil is wounddirectly around the motor shaft and a second or outer coil is woundaround the first or inner coil but without interfering with shaftdisplacement. Each coil is supplied with respective alternating currentsources which generate respective electromagnetic fields that alsogenerate a reciprocating motion of the motor shaft. The inner coil mayconduct direct current DC while the outer coil conducts alternatingcurrent AC. Alternatively, the inner coil may conduct alternatingcurrent AC while the outer coil conducts direct current DC, or both theinner coil and the outer coil may conduct alternating current AC. TheVCM may also include a countermass or counterbalance which is driven atan opposite phase (e.g., 180° phase lag) for cancelling some or all ofthe vibration caused by the motor. This avoids “chatter” from the partsand therefore does not irritate the operator or patient.

In some embodiments, the motor 166 may be a DC or DC brushless motor forcreating reciprocating displacement via a scotch yoke or similarmechanism. When activated, the DC motor causes a rotating crank to drivethe scotch yoke slider and the scotch yoke shaft in reciprocatingmotion. An adapter transmits the scotch yoke motion to the scotch yokeshaft. In other embodiments, the motor 166 is an amplified piezoelectricactuator (APA) that creates reciprocating displacement in the lowerrange, preferably 0.1 to 2.0 mm. One or more APA motors can be used inseries to increase displacement. Reciprocating motion is created by APAactuator expansion and contraction. In still other embodiments, aLangevin transducer can be used for the motor 166. A Langevin transducercomprises a plurality of piezoelectric elements arranged to cause a hornto vibrate to produce the reciprocating motion. A power source providesthe proper activation energy. Lateral displacement caused by overtonesproduced from the horn vibrating may be minimized by compressing thepiezoelectric elements. Accordingly, a standing wave is generated, whichpropagates to the clearing stem. In further embodiments, the motor 166is a solenoid motor. The solenoid is pulsed during activation such thatduring the pulse, a solenoid shaft is driven in one direction and whenthe pulse is terminated, a return spring restores the solenoid shaft tothe opposite direction. This action is repeated at the operativefrequencies. In still other embodiments, the motor 166 may be apneumatic motor that has a shaft which receives pneumatic pulses from apneumatic pulse generator via an air supply. A pneumatic motor diaphragmdistributes the pneumatic pulse evenly to the pneumatic motor shaft,thereby maintaining its alignment, while at the same time providing atightly-sealed motor configuration. The pneumatic pulse causes thepneumatic motor shaft to be driven in one direction while compressing areturn spring. Once the pneumatic pulse is terminated, the return springrestores the pneumatic motor shaft to the opposite direction. Thisaction is repeated at operative frequencies.

Since many modifications, variations and changes in detail can be madeto the described preferred embodiments, it is intended that all mattersin the foregoing description and shown in the accompanying drawings beinterpreted as illustrative and not in a limiting sense. Thus, the scopeof the invention should be determined by the appended claims and theirlegal equivalents. Now that the invention has been described,

What is claimed is:
 1. A device for in situ clearing of occlusivematerial, comprising: an aspiration conduit having at least one openingat an operative distal end, said aspiration conduit defining anaspiration lumen therein; an irrigation conduit disposed within andparallel to said aspiration lumen and terminating within said aspirationlumen a preselected distance from said at least one opening, saidirrigation conduit defining an irrigation lumen therein: and a handsethaving: (i) an aspiration port; (ii) aspiration tubing in fluidcommunication between said aspiration port and said aspiration lumen;(iii) an irrigation port; and (iv) irrigation tubing in fluidcommunication between said irrigation port with said irrigation lumen.2. The device as recited in claim 1, wherein said irrigation conduit isseparate from said aspiration conduit.
 3. The device as recited in claim1, wherein at least a portion of said irrigation conduit is attached tosaid aspiration conduit.
 4. The device as recited in claim 3, wherein atleast a portion of said irrigation conduit and said aspiration conduitare integrally formed.
 5. The device as recited in claim 1, wherein saidoperative distal end of said aspiration conduit has a distal tip made ofa different material than said aspiration conduit.
 6. The device asrecited in claim 5, wherein said distal tip is more flexible than saidaspiration conduit.
 7. The device as recited in claim 1, wherein said atleast one opening is located at a terminal end of said aspirationconduit.
 8. The device as recited in claim 7, wherein said at least oneopening is located a preselected distance from said terminal end of saidaspiration conduit.
 9. The device as recited in claim 1, furthercomprising a first valve interposed in fluid communication in saidaspiration tubing, and a second valve interposed in fluid communicationin said irrigation tubing.
 10. The device as recited in claim 9, furthercomprising an actuator simultaneously actuating said first and secondvalves.
 11. The device as recited in claim 10, further comprising a lockselectively retaining said actuator in at least one position.
 12. Thedevice as recited in claim 11, wherein said lock is at least one of aslide, pin, and plate.
 13. The device as recited in claim 1, furthercomprising a tubing junction having: (i) a first passage in fluidcommunication with said aspiration tubing; (ii) a second passage influid communication with said irrigation tubing; and (iii) a thirdpassage in fluid communication with said first and second passages. 14.The device as recited in claim 13, wherein said tubing junction furtherincludes a seal around at least one of said irrigation conduit and saidirrigation tubing in at least one of said second and third passages. 15.The device as recited in claim 13, wherein said handset furthercomprises a motor generating reciprocating motion, and a shaftmechanically connecting said motor and said tubing junction.
 16. Thedevice as recited in claim 1, wherein said handset further comprises amotor generating reciprocating motion, and a shaft mechanicallyinterconnecting said motor and at least one of said aspiration conduitand said irrigation conduit.
 17. The device as recited in claim 16,wherein said motor is at least one of a voice coil motor, apiezoelectric motor, a Langevin transducer, a DC motor, a solenoidmotor, and a pneumatic motor.
 18. The device as recited in claim 1,wherein said aspiration conduit and said irrigation conduit collectivelydefine a clearing stem, and further comprising a coupler located at saidoperative distal end of said clearing stem, said coupler including: (i)a clearing stem connector defining a chamber therein, said operativedistal end of said clearing stem disposed within said chamber; (ii) atube connector in fluid communication with said chamber, said operativedistal end of said clearing stem movable from said chamber to said tubeconnector.
 19. The device as recited in claim 18, wherein said couplerfurther comprises a lavage port in said clearing stem connector in fluidcommunication with said chamber, providing lavage fluid to clean saidoperative distal end of said clearing stem.
 20. The device as recited inclaim 18, wherein said coupler further comprises a ventilator port influid communication with said tube connector, providing ventilatoraccess to said tube connector.
 21. The device as recited in claim 20,wherein said coupler further comprises a diaphragm creating a fluidicseal around said clearing stem.
 22. The device as recited in claim 1,wherein said aspiration conduit and said irrigation conduit collectivelydefine a clearing stem; and further comprising a protective sleevecovering at least a portion of said clearing stem.
 23. A system for insitu clearing of occlusive material, comprising: a clearing stem having:(i) an operative distal end; (ii) an aspiration conduit defining anaspiration lumen therein, providing aspiration from said operativedistal end, and having at least one opening at said operative distalend; (iii) an irrigation conduit positioned interior to and terminatingwithin said aspiration lumen, said irrigation conduit defining anirrigation lumen therein; a handset having: (iv) an aspiration port; (v)aspiration tubing fluidically connecting said aspiration port with saidaspiration lumen; (vi) an irrigation port; and (vii) irrigation tubingfluidically connecting said irrigation port with said irrigation lumen;an aspiration source in fluid communication with said aspiration lumen,said aspiration source providing negative pressure for aspiration fromsaid operative distal end to said aspiration source; and an irrigationsource in fluid communication with said irrigation lumen, saidirrigation source providing irrigant to said irrigation conduit suchthat said irrigant flows from said irrigation source, through saidirrigation lumen, exits said irrigation conduit and is substantiallyaspirated away from said operative distal end of said irrigation conduitthrough said aspiration lumen in the direction of said aspirationsource.
 24. The system as recited in claim 23, wherein said irrigationconduit is separate from said aspiration conduit.
 25. The system asrecited in claim 23, wherein at least a portion of said irrigationconduit is attached to said aspiration conduit.
 26. The system asrecited in claim 25, wherein at least a portion of said irrigationconduit and said aspiration conduit are integrally formed.
 27. Thesystem as recited in claim 23, wherein said operative distal end of saidaspiration conduit terminates in a distal tip made of a differentmaterial than said aspiration conduit.
 28. The system as recited inclaim 27, wherein said distal tip is more flexible than said aspirationconduit.
 29. The system as recited in claim 23, wherein said at leastone opening is located at a terminal end of said aspiration conduit. 30.The system as recited in claim 29, wherein said at least one opening islocated a preselected distance from said terminal end of said aspirationconduit.
 31. The system as recited in claim 23, further comprising afirst valve controlling aspiration flow through at least one of saidaspiration tubing and said aspiration conduit, and a second valvecontrolling irrigation controlling irrigation flow through at least oneof said irrigation tubing and said irrigation conduit.
 32. The system asrecited in claim 25, further comprising an actuator simultaneouslyactuating said first and second valves.
 33. The system as recited inclaim 32, further comprising a lock selectively retaining said actuatorin position so as to maintain said first and second valves in at leastone of an open or closed position.
 34. The system as recited in claim33, wherein said lock is at least one of a slide, pin, and plate. 35.The system as recited in claim 23, further comprising a tubing junctionhaving: (i) a first passage receiving said aspiration tubing; (ii) asecond passage receiving said irrigation tubing; and (iii) a thirdpassage joining said aspiration tubing with said aspiration conduit andsaid irrigation tubing with said irrigation conduit, such that saidclearing stem extends from said tubing junction with said irrigationconduit disposed within said aspiration lumen.
 36. The system as recitedin claim 35, wherein said tubing junction further includes a seal in atleast one of said second and third passages creating a fluidic barrieraround said irrigation tubing within said tubing junction.
 37. Thesystem as recited in claim 35, wherein said handset further comprises amotor generating reciprocating motion, and a shaft connecting said motorand said tubing junction and transmitting said reciprocating motion tosaid clearing stem through said tubing junction.
 38. The system asrecited in claim 23, wherein said handset further comprises a motorgenerating reciprocating motion, and a shaft extending from said motorand transmitting said reciprocating motion to said clearing stem. 39.The system as recited in claim 38, wherein said motor is at least one ofa voice coil motor, a piezoelectric motor, a Langevin transducer, a DCmotor, a solenoid motor, and a pneumatic motor.
 40. The system asrecited in claim 23, further comprising a coupler located at saidoperative distal end of said clearing stem, said coupler including: (i)a clearing stem connector having a chamber receiving said operativedistal end of said clearing stem; (ii) a tube connector in fluidcommunication with said chamber and selectively attachable to a tubehaving occlusive material to be removed, said operative distal end ofsaid clearing stem is movable into said tube through said tubeconnector.
 41. The system as recited in claim 40, wherein said couplerfurther comprises a lavage port in said clearing stem connectorproviding lavage fluid to clean said distal end of said clearing stem.42. The system as recited in claim 40, wherein said coupler furthercomprises a ventilator port in fluid communication with said tubeconnector providing ventilator access to said tube connector and saidtube.
 43. The system as recited in claim 42, wherein said couplerfurther comprises a diaphragm creating a fluidic seal around saidclearing stem.
 44. The system as recited in claim 23, further comprisinga protective sleeve covering at least a portion of said clearing stem.